Transcript Cardiovascular

The Cardiovascular System
Blood
The Heart
Blood Vessels
Cardiovascular system
Functions:
Transports:
oxygen
carbon dioxide
nutrients
wastes
chemical messengers
Homeostasis of
pH
temperature
clotting
Disease Defense
Systemic Vessels
Blood = Plasma + Formed (Cellular) Elements
Plasma
• ~ 55% blood volume
• ~ 92% of plasma is water
• High dissolved oxygen content
• Dissolved proteins
• Albumins
• Globulins
• Fibrinogen
Cells
• ~ 45% blood volume
• RBCs ~ 99% of cells
• WBCs ~1% of cells
The Proteins in Plasma
• Albumins
– 60% of plasma proteins
– viscosity
• Globulins
– 35% of plasma proteins
• Immunoglobulins attack foreign invaders
• Fibrinogen
– React in clotting reaction
– Form fibrin (serum = plasma - fibrinogen)
Cellular Components
• RBCs (erythrocytes)~ 99% of all cells.
• ~ 1/2 blood volume.
Hematocrit = % of blood occupied by cellular components (~ RBC volume)
Lacks mitochondria,
ribosomes, nuclei
Life span = ~120 days
Scanning Electron Micrograph (SEM)
of Erythrocytes or Red Blood Cells (RBCs)
on the tip of a hypodermic needle.
Hemoglobin
Erythropoietin
Life and death of an RBC
Anemia
• Pernicious anemia
– Low Fe absorption – Vitamin B12 and
instrinsic factor
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Hemorrhagic anemia
Sickle cell anemia
Hypochromic anemia
Hemolytic anemia
polycythemia
Pernicious
anemia
Blood Types - ABO
What type?
What type?
Erythroblastosis fetalis
Granular Leukocytes (WBCs)
• Neutrophils
– 70% circulating leukocytes
– Highly active aggressive phagocytes
• Eosinophils (acidophils)
– Much less common
– Attracted to foreign compounds reacted with
antibodies
– Parasitic infections
• Basophils
– Relatively rare
– allergeries
– Release histamines.
Agranular Leukocytes
• Lymphocytes
– Primary cell of the lymphatic system
• T-cells attack foreign cells directly
• B-cells produce antibodies
• Monocytes
– Migrate into peripheral tissues
and differential into Macrophages
– Highly mobile phagocytic cells
– diapedesis
• Platelet cells (Thrombocytes)
– Fragments of Megakaryocytes
– enclosed packets of cytoplasm for blood
clotting
Never
Let
Monkeys
Eat
Bananas
Pulmonary circuit
- from heart
to lungs
back to heart
Systemic circuit
- from heart
to body
back to heart
Arteries = vessels that carry blood away from the heart.
Veins = vessels that return blood to the heart.
Capillaries = smallest vessels, found between smallest arteries
and veins. These are the exchange vessels.
The Heart
• Myocardium
• Chambers
• Valves
(one-way-flow)
• Pericardial Sac
Location of the Heart in the Thoracic Cavity
Epicardium
– Visceral pericardium
Myocardium
– Muscular wall of the heart
Endocardium
– Epithelium of inner surface
The Heart is Dual Pump
• Most of the heart is Myocardium
- Contractile Myocardiocytes
* Interconnected by intercalated discs
Position and Orientation of the Heart
Sectional Anatomy of the Heart
Blood Flow through Heart
RA -> ______ valve -> RV -> _____ valve -> pulmonary trunk
-> pulmonary ______s -> lungs -> pulmonary _____s -> LA ->
____ valve -> LV -> ___ valve -> ascending aorta -> aortic arch
Receives blood from systemic circuit
Superior vena cava
Inferior vena cava
Coronary veins
Return blood to coronary sinus then on to right ventricle
Foramen ovale open during embryonic development
Fossa ovalis after birth
Right Ventricle
Blood comes from right atrium to right ventricle through the
atroventricular (AV) valve
Right AV valve / Tricuspid valve
Three cusps of fibrous tissue
- Chordae tendineae
- Papillary muscles
- Pulmonary semilunar valve
Blood leaves Rt Ventricle via pulmonary Semilunar valve
to pulmonary trunk.
Branches to left and right pulmonary arteries
Valves of the Heart
How do papillary muscles work?
Heart Valves and Heart Sounds
• Closure of the AV
valves create the 1st
heart sound (‘lub’).
• Closure of the
semilunar valves
create the 2nd heart
sound (‘dupp’).
• Placement of a
stethoscope varies
depending on which
heart sounds and
valves are of
interest.
Coronary Circulation
Normal Functional Heart Anatomy
Congenital Heart Defects
Congenital Heart Defects
Congenital Heart Defects
The Cardiac Cycle
The Electrocardiogram
Recording of the electrical activities in the heart
P wave
= Atrial Depolarization
QRS complex
= Ventricular Depolarization
T wave
= Ventricular Repolarization
ECG
The Conducting System of the Heart
Heart cycle